Several specimens of Mycenastrum corium were collected for the first time at the Botanic Garden of the UNAM Biology Institute in the Pedregal de San Ángel Ecological Reserve (REPSA), México City. Of the five people who ingested the fungus, three showed no signs
of gastrointestinal distress while two suffered from severe flatulence and diarrhea six hours after ingestion. The collections are described and distribution of the species in Mexico and elsewhere is noted.